Most of the dosimetry work that is carried out at REB has direct or indirect applications to the assessment of radiation doses from bioterrorism events involving radiation. Accurate assessment of doses permits accurate projections of long-term cancer risks to be made. Since 2005, many of the bioterrorism studies at REB are funded under an Inter-Agency Agreement between NIAID and NCI. Examples of completed and continuing REB activities relevant of bioterrorism follow. Radioactive Fallout from Nuclear Weapons Test With regard to the studies of radioactive fallout from nuclear weapons test, the completed studies include: 1. The preparation of a web-based calculator for estimating individual radiation dose and thyroid cancer risk from I-131; and 2. The preparation of a report of a Congressionally-mandated feasibility study on exposure from all nuclear weapons tests. The continuing studies are: 1. The development of a joint methodology for assessment of radiation doses from nuclear tests conducted at Semipalatinsk 2. The acquisition of data on residential history, foodstuff consumption rates, and agricultural practices to be used in the joint methodology 3. As mandated by Congress, the assessment of doses and risks from nuclear tests conducted in the Marshall Islands; and 4. Archiving fallout published reports and putting into electronic form historical radiation monitoring data related to fallout. Evaluation of Consequences of Radiation Accidents With respect to the evaluation of the consequences of actual or hypothetical radiation accidents, a study was completed on the development of a database of stable chromosome aberrations for unexposed people, in order to separate, after a nuclear event, the persons who were mildly exposed from those with a baseline level. Continuing or new studies include: 1. The estimation of radiation doses by people affected by the Chernobyl accident 2. The rapid assessment of individual doses from external irradiation following a nuclear event; and 3. The evaluation of the organization, implementation, and efficacy of the countermeasures used after the Chernobyl accident. Development of New Methods Regarding the development of new methods, completed activities include: 1. The development of improved bio dosimetry procedures or instrumentation making use of optically-stimulated luminescence and electron paramagnetic resonance 2. Corroboration of analytical dosimetry estimates via biodosimetry measurements; and 3. The assessment of doses per unit intake of I-131 for healthy people and for people suffering from thyroid diseases. 4. Archiving fallout published reports and putting into electronic form historical radiation monitoring data related to fallout. Training and Communication A number of studies or activities are also devoted to training and communication. Completed activities include: 1. The organization of special sessions on radiation dosimetry at the 2004 annual meeting of the Health Physics Society and at the BioDosEPR Symposium in July 2006; and 2. The preparation of a special issue of Radiation Research describing how dosimetry methods are applied in the assessment of medical, occupational, and environmental radiation doses. Continuing activities include: 1. Participation in programs of international agencies, e.g., the International Atomic Energy Agency, the International Commission on Radiological Protection, and the United Nations Scientific Committee on the Effects of Atomic Radiation on the assessment of doses 2. Participation in the preparation of reports of the National Commission on Radiation Protection and Measurements on retrospective dose reconstruction; and 3. The organization of training in radiation sciences of personnel involved in the mitigation of nuclear events.